how much should i be looking at

[HKsilvia]

let say i bought a knock off bumper (from VIS), condition is not really good comparing to those brand name.
if i take it to a shop and they intall for me with:
- PPG paint
- a very decent paint job on the bumper only and last very long
- match my car's original color (burgandy with metallic)
- smooth out all the edges that was not perfect since its a knock off bumper
to make it simple they are going to make this knock off as good as real brand name bumper

how much you guys think i should be paying
thx for reading